In related art, as a method of manufacturing an optical transmission module for optically coupling an optical cable and a photoelectric conversion element, for example, there exists a manufacturing method using the optical transmission module tester described in Japanese Unexamined Patent Application Publication No. 2001-108863. In this type of manufacturing method (to be referred to as “manufacturing method according to related art” hereinafter), two optical transmission module components are moved to the left/right, up/down, and forward/backward, and then further rotated to optically couple the two optical transmission module components. Because the manufacturing method according to related art involves not only three-dimensionally moving but also rotating the two optical transmission module components in this way, a complicated operation process is required.